STRATHAM — A Catholic Medical Center emergency room physician was the Merrimack man who died Monday afternoon after losing control of his motorcycle and colliding with an SUV stopped at a traffic light on Portsmouth Avenue (Route 108).

Police said Leon Haas, 61, suffered fatal injuries in the accident in front of the Shaw’s Supermarket Plaza at 2:02 p.m. Haas was not wearing a helmet.

The driver of the SUV, 44-year-old Kyle Smith of Newfields, was not injured.

The State Police Crash Analysis and Reconstruction Unit determined that Haas was driving south on Portsmouth Avenue and lost control of his 2009 Harley Davidson, which caused him to crash into Smith’s southbound SUV.

Haas was a longtime CMC emergency room physician and employees are mourning his sudden loss, a hospital spokesman said.